Notes

These data record the \((x,y)\) locations and ages of bramble canes in a
field \(9\) metres square, rescaled to the unit square.
The canes were classified according to age as either newly emergent,
one or two years old. These are encoded as marks 0, 1 and 2 respectively
in the dataset.

The data were recorded and analysed by Hutchings (1979)
and further analysed by Diggle (1981a, 1981b, 1983),
Diggle and Milne (1983), and Van Lieshout and Baddeley (1999).
All analyses found that the pattern of newly emergent canes
exhibits clustering, which Hutchings attributes to ``vigorous
vegetative reproduction''.

References

Diggle, P. J. (1981a)
Some graphical methods in the analysis of spatial point patterns.
In Interpreting multivariate data, V. Barnett (Ed.)
John Wiley and Sons.